I am unsure that anything can be mastered in a week, even if this book's subtitle is "Master neuro-linguistic programming in seven simple steps." Though, now that I look at it, the title doesn't actually say "master NLP in a week," it just says "master in seven steps" and "nlp in a week."
Anyway, NLP in a week, seven simple steps. The idea is one can change one's behaviour by changing one's thinking, and change one's emotional state by changing one's behaviour (ergo, change one's emotional state by changing one's thinking). Given that pretty much the only thing one truly has is her consciousness (thoughts, perceptions, all elements of the same thing), one can assume changing one's interpretation of reality can change the one's reactions to said reality.
More simply put, if one assumes the world is a bad place, the world is a bad place, and you see only the pain, misery, and hurt. You assume everyone is out to take advantage of you. If you see the world as a happy place, you might be suckered sometimes, but the journey will be a hell of a lot more fun.
My default is to assume the worst. It would probably be good if this was coupled with a habit of planning accordingly, but I don't. I usually just go along until, surprise, here is reality, and, oh, I was wrong, I do, indeed, have stunningly bad luck. You know, someone has to have the worst luck, might has well be someone who is mostly oblivious to it.
But, well, what if all of this really isn't that bad?